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    <title>Document</title>
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<body>
    <div></div>
    <script>
        console.log(location.search);
        // 1.先去掉？ substr('起始的位置'，截取几个字符（不写则默认到最后）)
        var params = location.search.substr(1)
        console.log(params);
        // 2.利用 = 把字符串分割成数组split('=')
        var arr = params.split('=')
        console.log(arr);
        //  3.把数据写入div
        var div = document.querySelector('div')
        div.innerHTML = arr[1] + '欢迎您';
    </script>
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